Question

change into passive voice- They found him guilty of murder.

Answer 1

He was found guilty of murder.
                 or it can also be written as
He was found guilty of murder by them.

Answer 2

In a sentence with an active voice, the subject performs the action which is denoted by the verb. In other words, the subject is the doer of the action. Whereas in a passive voice, the subject is not active but by the verb is acted upon.

Passive voice is the voice used to show an interest in the object or person who experienced the action rather upon the action performer. In passive voice, a subject is an important thing.

The sentence when written in passive voice, it would be written as:

He was found guilty of murder by them.